324 



Dr. R. McCarrison. 



Results of the Experiment. 



The results of this experiment are shown in the following Table : — 





No. of 

 mothers. 



No. of 

 mothers 

 goitrous. 



No. of 

 kids 

 born, 



No. of 

 kids 

 born 

 alive 

 and 



healthy. 



No. of 

 kids 

 still- 

 born. 



No. of 

 kids still- 

 born, but 



fully 

 developed. 



No. of 

 kids still- 

 born, 

 macerated, 

 hairless, 

 and ill- 

 developed. 



No. of 

 kids bom 



with 

 congenital 



goitre. 



Class A— 



Receiving cultures ... 

 ClaBS B (controls) — 



Class C— 



12 



4 

 4 



1 



12 





 2 



1 



11 



3 

 2 



•1 



1 



2 

 1 



1 



10 



1 

 1 













 1 







10 



1 











11 





 2 







Summary, 





Experimental. 



Controls. 



Stillborn, hairless, ill-developed kids 



Stillborn, but fully developed kids 



Congenitally goitred kids 



1, or 9 per cent. 



10, or 90 „ 

 0, or 



11, or 100 „ 



4, or 66 - 6 per cent. 



1, or 16 -6 



3, or 16 -6 „ 



2, or 33 -3 „ 



It is clear from these results that there is a marked difference in the three 

 classes of animals. 



With regard to the mothers themselves : it was not observed that the 

 goitres of those in the first and third classes underwent any considerable 

 increase in size during pregnancy. Amongst the mothers in Class B, 

 however, two of the unmuzzled animals developed small goitres during 

 pregnancy. 



With regard to their offspring: 100 per cent, in the first class were 

 goitrous, while 90 per cent, were stillborn, macerated, hairless, ill-developed, 

 and goitrous foetuses, death having been intra-uterine (Plate 12, fig. 1). 



In the second class, on the other hand, none of the offspriug showed all 

 these pathological characteristics at one and the same time. Three of the 

 five kids born in this class were perfect in health and development, e.g., 

 60 per cent. One had slight goitre which disappeared shortly after birth. 

 A fourth was stillborn and goitrous, but as it was otherwise well developed, 

 covered with a thick coat of healthy hair (fig. 2) and showed no signs of 

 maceration, its death was probably extra-uterine. The fifth was born 

 prematurely but was not goitrous. Its premature birth might well have 



